Bears linebacker Geno Hayes admitted it won't be possible to duplicate what Brian Urlacher brings to the field.
"You can't replace that," said Hayes, who will start Sunday at Minnesota for the Bears on the strong side. "Urlacher is one of a kind. You can try to play like that ... but you can't make too many guys like Brian Urlacher. He's a special guy."
Hayes started 13 games for the Bucs last season and 42 over the past three years.
But Hayes spent a lot of time starting on the strong side with Nick Roach in the middle during training and preseason, while Urlacher was sidelined with a knee injury. Roach will be back in the middle Sunday with Urlacher (hamstring) out.
"It helps because Geno Hayes has played a lot of football," coach Lovie Smith said. "And Nick Roach has played a lot of positions for us. We have (seven-time Pro Bowl weak-side linebacker) Lance Briggs, too. So we feel like we'll be OK. (But) we can't replace Brian. It's hard to do that."
In addition to leading the team in tackles, Urlacher makes all the defensive calls, is a team captain and has an unparalleled knowledge of the defense.
"He's a great player, and he's one of the leaders," Smith said. "Him being in the huddle helps. So we're going to miss him. I can't belittle that at all. We're missing a great player. You just have to Plan B. Plan B for us is pretty good, if you do lose a player like that."
By the numbers:
While the Bears' 4.28-yard average on first downs continues to be the NFL's worst, they've improved to No. 12 in third-down conversions, up six spots from two weeks ago.
"Two weeks in a row we're starting to make some strides as far as being in manageable third downs," offensive coordinator Mike Tice said. "(That's) allowing us to convert more on third down than we have at any point in the year, in that 50-percentile."
The Bears converted 6 of 12 third downs against the Seahawks and had a 57.9 percent success rate (11 of 19) against the Vikings a week earlier.
Quarterback Jay Cutler is No. 7 in the NFL with a 92.8 passer rating on third-downs. Cutler remains No. 1 in the NFL with a fourth-quarter passer rating of 134.9.
Coming up short:
One of offensive coordinator Mike Tice's favorite themes is: "When you get a chance to make a play, make it."
So the failure last week to pick up 1 foot on fourth down at the Seahawks' 15-yard line in the second quarter didn't sit well. On the Bears' two other red zone opportunities they scored touchdowns.
"We still have to make plays when we have a chance to make them," Tice said. "When the man calls on you to make fourth-and-inches, ... you make it. Those are the disappointing things in the game."
Cornerback Tim Jennings (shoulder), wide receivers Brandon Marshall (coach's decision) and Earl Bennett (concussion), running back Michael Bush (ribs) and defensive tackle Stephen Paea (foot) did not participate in Wednesday's first practice of the season inside the Walter Payton Center.
Neither did linebacker Brian Urlacher (hamstring), who has already been ruled out.
"All we can tell you is he's out this week," coach Lovie Smith said of Urlacher, who could miss the remainder of the regular season. "Exactly when he's coming back, I don't know. He's coming back some time."
Marshall and Bush are expected back at practice today.
Offensive lineman Gabe Carimi (hamstring), guard Chris Spencer (knee) and wide receivers Alshon Jeffery (knee) and Devin Hester (concussion) practiced but were limited.
For the Vikings, defensive end Jared Allen (shoulder/back) did not practice, while tight end Kyle Rudolph (shoulder), offensive tackle Phil Loadholt (knee), center John Sullivan (ribs/knee) and cornerback Antoine Winfield (knee) were limited. Minnesota also put WR Percy Harvin on injured reserve because of an ankle injury.